Piston

ABSTRACT

A piston in which the piston ring arranged in the groove following the piston top land is securely supported by a piston ring support that consists of an annular disc retained under stress with its inner circumference at the piston, and more particularly between the upper edge of the piston ring groove and the piston ring itself.

United States Patent Hoffmann [451 Apr. 18, 1972 PISTON [56] ReferencesCited [72] Inventor: Heinrich Hoffmann, 'Stuttgart-Geroksruhe, I DSTATES PATENTS f 2,996,342 8/1961 Daub ..277/129.5 Assignw Daimler-BenzAktiengesellschaft, Stuttgart- 2,415,984 2/1947 Ballard ..277/l88Unterturkheim, Germany Primary Examiner-Samuel B. Rothberg [22]Attorney-Craig, Antonelli & Hill [21] Appl. No.: 5,286

[57] ABSTRACT [30] Foreign Application Priority Data A piston in whichthe piston ring arranged in the 'groove f ollowing the piston top landis securely supported by a piston Jan. 23, 1969 Germany ..P 19 03 257.6ring Support that consists of an annular disc retained under stress withits inner circumference at the piston, and more par- [52] US. Cl"277/1895, 277/193 ticularly between the upper edge of the piston ringgroove and [51] Int. Cl ..F16 9/22, F16] 9/00 the piston ring itselfi[58] Field ofSearch ..277/l89.5,l93,188,192,197

7 Claims, 2 Drawing Figures PATENTEDAPRmmn 3.656.770

INVENTOR HEINRICH HOFFMANN BY Z MhmJqM ATTORNEYS PISTON The presentinvention relates to a piston in which a piston ring essentiallyrectangular in cross-section with a piston ring support is arranged inthe piston ring groove following the piston top land.

The present invention aims at preventing far-reachingly the predominantwear of the upper groove flank and therewith to avoid an enlargement ofthe play in the axial direction. As a result thereof, an increase of theoil consumption and of the piston blow or piston-ring blow-by quantityis no longer possible.

This is achieved according to the present invention in that the pistonring support consists of a wear-resistant annular disc which is retainedunder stress with its inner circumference at the piston between theupper rim of the piston ring groove and the piston ring.

It is thereby to be considered as advantageous that the piston ringreceives by means of the piston ring support a strong, rigid andmechanically reinforced support in the piston ring groove, and that anaxial play is almost not present at all, i.e., is practically absent.

In a preferred type of construction according to the present invention,a second groove may be provided for the piston ring support which startsfrom the groove bottom of the piston ring groove. In this manner, thepiston ring support is fixed in the axial direction.

According to a further feature of the present invention, the piston ringsupport may be provided at its inner circumference with preferablysemi-circularly shaped recesses. For the purpose of slipping the pistonring support over the top land of the piston, a bending apart of thepiston ring support under stress is made possible thereby.

Additionally, the present invention proposes that the piston ringsupport abuts only with the web portions between the recesses.Furthermore, the outer diameter of the piston ring support may besmaller than the piston diameter in order to avoid under allcircumstances a contact with the cylinder wall.

Accordingly, it is an object of the present invention to provide apiston which avoids by simple means the aforementioned shortcomings anddrawbacks encountered in the prior art.

Another object of the present invention resides in a piston whichprecludes far-reachingly the wear of the upper groove flank and thuseliminates an increase in play in the axial direction on the part of thepiston ring.

A further object of the present invention resides in a piston whicheffectively minimizes the danger of increase in the oil consumption andpiston blow quantity.

Still a further object of the present invention resides in a piston foran internal combustion engine in which the piston ring is secured morerigidly in the piston ring groove.

These and further objects, features, and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accom panying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIG. 1 is a top plan view on a piston ring support in accordance withthe present invention; and

FIG. 2 is a partial'cross-sectional view through a piston with a pistonring and a piston ring support in accordance with the present invention.

Referring now to the drawing wherein like reference numerals are usedthroughout the two views to designate like parts, and more particularlyto FIG. 1, semi-circularly shaped recesses 2 are regularly distributedalong the inner circumference of the piston ring support 1 consisting ofsteel. The slipping over of the piston ring support 1 over the top land3 of the piston 4 is made possible by the accommodation of a slot 5. Thepiston ring support 1 is seated as can be seen from FIG. 2 with the webportions 6 in the groove 7 above the piston ring 8 disposed in thepiston ring groove 9. The outer diameter of the piston ring support 1 issmaller than the diameter of the piston 4.

While I have shown and described only one embodiment in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art, and I therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are within the scope of thoseskilled in the art.

Iclaim:

I. A piston in which a piston ring with a piston ring support isarranged in the piston ring groove following the piston top land,characterized in that the piston ring support consists of an annulardisc which is provided with alternate web portions and recesses alongits internal circumference and is retained under stress with itsinternal circumference retained in the piston only at the web portionsthereof between the recesses between the upper edge of the piston ringgroove and the upper surface of a second groove adjacent said pistonring groove and extending inward therefrom.

2. A piston according to claim 1, characterized in that the piston ringsupport is of essentially rectangular cross-section.

3. A piston according to claim 1, characterized in that the piston ringsupport is provided with a slot between'its inner circumference and itsouter circumference.

4. A piston according to claim 2, characterized in that said recessesare of substantially semi-circular shape.

5. A piston according to claim 4, characterized in that the outerdiameter of the piston ring support is smaller than the diameter of thepiston.

6. A piston according to claim 1, characterized in that said recessesare of substantially semi-circular shape.

7. A piston according to claim 1, characterized in that the outerdiameter of the piston ring support is smaller than the diameter of thepiston.

1. A piston in which a piston ring with a piston ring support isarranged in the piston ring groove following the piston top land,characterized in that the piston ring support consists of an annulardisc which is provided with alternate web portions and recesses alongits internal circumference and is retained under stress with itsinternal circumference retained in the piston only at the web portionsthereof between the recesses between the upper edge of the piston ringgroove and the upper surface of a second groove adjacent said pistonring groove and extending inward therefrom.
 2. A piston according toclaim 1, characterized in that the piston ring support is of essentiallyrectangular cross-section.
 3. A piston according to claim 1,characterized in that the piston ring support is provided with a slotbetween its inner circumference and its outer circumference.
 4. A pistonaccording to claim 2, characterized in that said recesses are ofsubstantially semi-circular shape.
 5. A piston according to claim 4,characterized in that the outer diameter of the piston ring support issmaller than the diameter of the piston.
 6. A piston according to claim1, characterized in that said recesses are of substantiallysemi-circular shape.
 7. A piston according to claim 1, characterized inthat the outer diameter of the piston ring support is smaller than thediameter of the piston.